The present invention relates to an apparatus for inserting a foldable item, e.g., a foldable intraocular lens and the like, into an eye. More particularly, the invention relates to such an apparatus constructed so as to be distally loaded with the item to be inserted.
An intraocular lens is implanted in the eye, e.g., as a replacement for the crystalline lens after cataract surgery. Intraocular lenses often include an optic, and preferably at least one flexible fixation member, e.g., a haptic, that extends from the optic and becomes affixed in the eye to secure the lens in position. The optic normally includes a transparent or optically clear optical lens. Implantation of such lenses into the eye involves making an incision in the eye. It is advantageous, e.g., to reduce trauma and speed healing, to have the incision sized as small as possible.
Intraocular lenses are known which are foldable for ease of insertion into the eye. A substantial number of instruments have been proposed to aid in inserting such a foldable lens in the eye. Many of these instruments involve pre-folding the lens before the lens is placed in the insertion device. While this hand folding allows the lens to be inserted through a relatively small incision, it is time consuming and the added handling can damage the lens.
Hauser U.S. Pat. No. 4,763,650 discloses an insertion device in which a deformable lens is grasped in its undeformed state in a pair of detachable jaws. The jaws are held stationary while a ramp and a thin walled tube are moved forward. The resulting ramping action causes the jaws to be drawn into the tube and to compress around the lens. The jaws are detached from the remainder of the device as the lens is inserted in the eye. It would be advantageous to employ a lens insertion system which did not require a ramp and/or which remains in tact throughout the lens insertion process.
Other devices, such as those described in Jampel et al U.S. Pat. No. 4,747,404 and in Baccala et al U.S. Pat. No. 4,785,810, use loading systems to fold the lens into the insertion apparatus and/or fold the lens through a longitudinally extending slot in the insertion apparatus. Such loading systems are relatively complex, while the relatively large longitudinally extending slots tend to cause problems in inserting the lens in the eye relative to using a substantially unbroken delivery tube.